Nov 20 2017

Restart as in close the game, log in again and play with the ponies you have...not as in delete all of your progress, no need for that. Same way you can close the game and pick up where you left it at a later date, yeah? Do that.

Oct 29 2017

I also had this issue, but it was recently fixed. The fix is slightly broken, but exists anyway. Make sure to update your game first.
The Ground Pound and whatever the other move was called can be found in the Other tab now. If the tab is empty and your game is the latest version (make sure to use the launcher first), close the game and reopen it and check the Other tab instantly when you get in game and they should be there. They have a tendency to disappear during gameplay for whatever reason, if they do disappear just restart the game and they'll be back.